Impact of Ti and Fe on the Microstructure and Properties of Copper and Copper Alloys

Abstract

The paper discusses issues related to the technology of melting and processing of copper alloys. An assessment was made of the impact of titanium and iron introduced in the form of pre-alloy - Ti73Fe master alloy on the microstructure and selected properties of pure copper and copper-silicon alloy. There are known examples of the use of titanium and iron additive to the copper alloy. Titanium as an additive introduced to copper alloys to improve their properties is sometimes also applicable. In the first stage of the study, a series of experimental castings were conducted with variable content of Ti73Fe master alloy entering copper in quantities of 5 %, 15 %, 25 % in relation to the mass of the metal charge. In the second stage, a silicon additive was introduced into copper in the amount of about 4 % by weight and 0.5 % and 1 % respectively of the initial Ti73Fe alloy. Thermodynamic phase parameters were modelled using CALPHAD method and Thermo-Calc software, thus obtaining the crystallization characteristics of the test alloys and the percentage of structural components at ambient temperature. Experiments confirmed the validity of the use of Ti73Fe master alloy as an additive. The pre-alloy used showed a favourable performance, both in terms of addition solubility and in the area of improvement of strength properties. Changes were achieved in the microstructure, mainly within the grain, but also in the developed dendrites of the solid solution. Changes occur with the introduction of titanium with iron into copper as well as to two-component silicon bronze.